A non-reciprocal device such as an isolator or circulator is incorporated, for example, in a mobile communication device such as a mobile telephone set or wireless device, or in a communication device used in the mobile communication base station. A typical non-reciprocal device comprises a gyromagnetic component formed of a soft ferrite body and a center electrode, a magnetic component such as a permanent magnet and electric components such as matching capacitors and terminal resistors, all housed in a magnetic metal case functioning as a yoke.
The center electrode is combined with the soft ferrite body, and to the assembly is applied a DC magnetic field by the permanent magnet. The center electrode comprises a plurality of terminal portions, and one end of it is placed on one surface of the soft ferrite body and is grounded to the metal case as a grounding portion. The terminal portions of the center conductor are formed so as to be arranged with a specified angle between each other. The fore-ends of the terminal portions are connected to said electric components and are led to the outside of the metal case to form external terminals.
By the way, a non-reciprocal device of this type is generally surface-mounted on and incorporated in the component-mounting board of the communication device. However, since the center conductor is formed of a very thin copper sheet or the like, it is difficult to properly position it as an external terminal as it is. Accordingly, terminal structures for securing the same planarity in the external terminals and the metal case have been proposed up to now.
For example, JP 2003-124,711A (Patent 1) discloses a non-reciprocal device having a terminal holding board with tab terminals fixed thereon. JP H10-294,606A (Patent 2) discloses a non-reciprocal device provided with a contact supporting member. U.S. Pat. No. 6,337,607B1 specification (Patent 3) discloses a structure in which terminals are formed by fitting a component-mounting board into each of the slots toward the inside of the case.
In the terminal structures of the conventional non-reciprocal devices, Patent 1 requires tab terminals and a terminal holding board, and Patent 2 requires contacts and a supporting member, and Patent 3 requires a plurality of component-mounting boards. Consequently, any of Patents 1 to 3 has a problem that the number of components and the man-hour for assembly are large.